1. Field of the Invention
The present invention relates to a transmission for use with an internal combustion engine, in which the transmission includes a parking lock mechanism, and to a vehicle including the locking transmission.
2. Description of the Background Art
Various examples of transmissions for internal combustion engines have been proposed, in which a parking position of the transmission can be selected in response to an operation of a shift lever, and in which the transmission includes a parking lock mechanism for restricting rotation of a drive shaft. Such restriction takes place when the vehicle is stopped, the parking position is selected, and then the internal combustion engine is stopped.
One example of a known transmission including such a parking lock mechanism is disclosed in Japanese Laid-Open Patent No. 2004-353739. In the transmission described in this reference, a parking actuator, that is separate from a gear shift actuator, is controlled and driven by a control device to activate the parking lock mechanism.
As an embodiment in Japanese Laid-Open Patent No. 2004-353739, a configuration is disclosed wherein, if an electric motor which forms a parking actuator is driven, an engaging member is caused to project through a pinion-rack mechanism and a coil spring, whereupon a tooth at an end of the engaging member is engaged with a parking gear fitted on an input power shaft of a speed change gear. As a result, rotation of the input power shaft is restricted.
Since the conventional parking lock mechanism is configured such that a power transmission system is formed as an independent apparatus which is separate from a shift change mechanism, and is driven by an actuator provided for exclusive use by the independent apparatus, it includes a great number of parts and increases the size of the internal combustion engine.
The present invention has been made in view of the above described situation, and it is an object of the present invention to provide a transmission for use with an internal combustion engine, wherein a parking lock mechanism is formed commonly with an upstream side portion of a power transmission system of a shift change mechanism, to reduce the number of parts required, and which can be incorporated compactly in the shift change mechanism to reduce the size of the internal combustion engine.